Aquatic plants require CO2 to grow and remain in optimal condition. The Fluval Pressurised CO2 kit ensures that optimal levels of CO2 are avalible in the aquarium to maintain vigorous, lush and vibrant aquarium plants. This complete CO2 system is perfect for planted aquariums from 57 litres to 151 litres and is simple to install and use. The Kit Includes: * One Fluval Pressurised CO2 cylinder with a stand, * An internal CO2 diffuser, * A visual bubble counter, * A regulator valve * Tubing (1 metre) * Replacement cannisters available - see related products Why use CO2? All planted aquariums lack CO2, unless they are supplemented with it. In fact, 40 to 50% of a plants dry weight is composed of carbon, for optimal conditions of aquarium plants some CO2 supplement is necessary. The CO2 kit from Fluval will ensure that the most important nutrient is available to plants in order to maintain vigorous, lush and vibrant growth. What we think.. The kit comes well packed in a sturdy box with all the fitments neatly laid out. There is a full explanatory guide included which contains photos and diagrams. We haven\'t used the kit ourselves yet but the pressure regulator which is often the failing point of these kits seems really good quality. We haven\'t received any negative feedback from customers regarding this product and are looking to try the product out in a shop display shortly!